| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] [v-ing] [prep] a | 7866 |
|
| 2 | to [be] [v-ing] [prep] | 1895 |
|
| 3 | to [be] [prep] a | 848 |
|
| 4 | to [be] [v-ing] a | 490 |
|
| 5 | to [v-ing] [prep] a | 202 |
|
